1. Odyssey, by Michael P. Kube-McDowell
2. Suspicion, by Mike McQuay
3. Cyborg, by William F. Wu
4. Prodigy, by Arthur Byron Cover
5. Refuge, by Ron Chilson
6. Perihelion, by William F. Wu

A man without memory, stranded on an icy asteroid. His only chance for survival is locked within a band of mining robots who are dutifully
searching the surface for a mysterious object known as the Key to Perihelion.
His name is Derec. His journey will take him to a city different from any he has ever known. A fantastic metropolis beyond his dreams..."

And so begins the story of Derec and Ariel (and assorted others) who start out very young (teens?) in this and the following series (Robots and Aliens) and turn up for encores older, a little sadder and (perhaps) wiser in the Robot Mystery series written after Asimov's death.

Six short books (about 6 hr. each in these TTS audio versions) make up the Robot City series that was proposed by Asimov to some younger
writers.

Each book begins with a short essay by Asimov that is somewhat related to the book (Part 00 in each audiobook).